


Lima Beans

by aisu10



Category: The Avengers (2012)
Genre: AND IT'S CUTE, CUTE BBY BRUCE, De-Aged Bruce, Domestic Avengers, GET PEPPER, Gen, HE'S 5 YEARS OLD, Other, also some angst, but mostly adorableness, daddy!Tony, lots of adorableness, mommy!Pepper, not an au, too much adorableness
Language: English
Status: In-Progress
Published: 2012-08-07
Updated: 2012-08-29
Packaged: 2017-11-11 15:16:48
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 13,171
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/479898
Author URL: https://archiveofourown.org/users/aisu10/pseuds/aisu10
Summary: <blockquote class="userstuff">
              <p>Bruce is turned into a five-year-old by a mysterious villain and Pepper and Tony have to take care of him while the other Avengers track down the culprit.</p>
            </blockquote>





	1. Chapter 1

It's ten in the morning and Tony has finally gotten up. Pepper is already gone, off to do who knows what, and Tony doesn't even know if Bruce ever made it to bed. Tony heads straight for the lab in his tank top and sweats, not even stopping for breakfast - he knows Pepper will track him down and bring him a coffee soon anyway, she _always_ does - and is surprised to find the place a mess. Well, messier than it usually is. Papers and discarded machinery litter the ground and a table's been knocked over in the far corner of the room. Tony surveys the damage with a cocked eyebrow and a frown before his gaze falls on the broken window. It's not Hulk-sized, which is good - great, even. That means someone other than his best-friend-turned-lover Bruce Banner was the cause of the damage. As he steps into the middle of the room, tapping the arc reactor with his forefinger crossly, Tony decides to ask his trusty AI what the deal is. 

"Uh... JARVIS?" Tony calls, brow furrowed, "What happened?" 

"Sir, it appears we've been attacked," JARVIS's perpetually calm voice responds from everywhere around him. 

"Uh, tell me something I don't already know." Tony looks around and kicks up some of the papers on the ground, still frowning. "Where's Bruce?" 

"That's precisely the problem, sir. He's still in the room." 

"Where?" 

Tony looks around yet again, as if he might have missed Bruce the first ten times he scanned the room. 

"Behind the table, sir. But sir, I must warn you. Dr. Banner has changed." 

"JARVIS, don't play games with me. I know The Hulk doesn't fit behind a table. Or even a bus, for that matter." 

JARVIS doesn't reply as Tony approaches the table, trying, "Bruce?" and sticking his tongue out at the ceiling when he gets no response, as if to tell his AI 'I'm right, you're wrong.' But when he peeks over the side of the fallen piece of furniture he realizes that he was the one who was wrong. Very wrong. 

Behind the table cowers a small child, all curly brown hair and skinny legs and too-large glasses. All he's wearing is an oversized purple button-up that is far too familiar to Tony. 

"Bruce?" Tony gasps, in a way that's both over-dramatic and maybe not dramatic enough for such an impossible situation. Either way, it's dramatic, and Bruce's eyes grow two sizes at the sound of a big man who he probably doesn't even know calling his name. 

Something really awful has happened, Tony decides in a panic. He knows that Bruce wasn't working on age potions or searching for the fountain of youth in here, so it must have been an outside force. Some supervillain must have broken in and tested some de-aging ray on Bruce while he was working in the lab. Maybe as a way to neutralize The Hulk. That might explain the broken window and all the shit everywhere. But no matter the cause or motive, shit, Bruce has been reduced to a five year old and Tony has no idea what to do about it. 

"Oh my god. Oh my god," Tony whines, horrified, "Bruce. Bruce, what happened to you? What went wrong?" 

And then the tiny Bruce's eyes well up in a zillion tears that flow freely down his pink cheeks, and he balls his fists and cries out in a surprisingly loud and forceful voice: "I'm not a monster!" 

Immediately Tony feels awful and he wishes he could kick himself in the face because, _fuck_ , he's the most insensitive, thoughtless jackass in the world. The last thing a young Bruce Banner would want to hear is that there's something wrong with him. Tony recalls a night when Bruce got drunk and spilled it all, his arm draped over Pepper's shoulders as he told them about how his father abused him and called him a freak over and over, and how Bruce could do nothing but cry and curl up under his bed and wish he was normal. And here is that same tiny Bruce, with the same fucking insecurities that he's always had, and Tony had one chance to gain his trust and he's already fucked it up. But Tony knows he's got to fix this, somehow. Bruce means the world to Tony and he can't lose him, he just can't. 

"Bruce, no, I didn't mean it like that," Tony apologizes, pulling the table out of the way and kneeling down to talk to Bruce on his own level. Bruce backs away, shies from Tony's outstretched hands, cowers against the wall. His face is wet all over and his crying is silent between frequent sniffles. Tony knows he has to fix this fast or the kid will never trust him. 

"Listen, Bruce, it's gonna be alright. I love you, okay? There's nothing wrong with you, I promise. You're not a monster. Look, I'm going to take care of you. You've got to let me take care of you, Bruce. I'm gonna take you to the kitchen get you some milk, or whatever you like, and something to eat, and later we'll do some kiddie science experiments like growing some fucking lima beans in a cup or something, right? Science. You love science. I promise everything’ll be okay - cross my arc reactor and everything. Just let me take care of you and everything’ll be fine." 

Bruce watches him through teary eyes as he makes his sloppy stream of promises, but when Tony finally finishes, Bruce wipes his face on the long purple sleeve of his shirt and nods hesitantly, shakily. 

"Oh, thank god. Okay, Bruce, I'm going to pick you up now, is that okay?" Tony's very careful as he inches forward and holds out his hands again. Bruce nods again, sniffing, and Tony picks him up. He weighs practically nothing and when Tony stands with him he clings to his shirt and hides his curly-haired head under Tony's chin. Tony can feel him shaking still but he's not sniffling anymore. 

"JARVIS?" Tony calls as he carries Bruce out of the lab and towards the elevator down to the kitchen. 

"Shall I call SHIELD?" JARVIS replies, already one step ahead. 

"Yeah, and Pepper. Get Pepper." 

\---------------

Tony takes Bruce to the kitchen and sets him down in a chair at the counter. He looks in the fridge and finds a carton of some weird soy milk that Pepper insisted on buying and Bruce had agreed with her, because he always takes her side. That's not even fair, is it? Tony had Pepper first, anyway. Then Bruce had just wormed his way in - well, maybe it was more like Tony and Pepper begged him to join them. Either way, it isn't really fair. Tony rolls his eyes at the thought and then remembers that Bruce is currently a teary five-year-old and Tony needs to stop getting distracted by the intricacies of his triad relationship and take care of him. 

"Okay, I've got this... Soy milk, here, or I can just give you water or soda or whatever you want, and I think I've got some cookies around here somewhere, or... There's a whole pack of cheese sticks, here, Bruce, do you like cheese sticks? Who even bought these?" 

Tony looks over his shoulder at Bruce, who shrugs. His whole body is turned inward, as if he's trying to shrink more than he already has. Tony sighs gently and turns to Bruce with the milk carton. 

"You can tell me what you want, Bruce. Or maybe you're not hungry at all," Tony says with a frown as he places the milk carton on the countertop, "Just say what's on your mind." 

Bruce is silent for a moment, then he opens his mouth to ask in a small voice, "Who are you?" 

And Tony almost laughs, because of course he'd forget to tell the kid his name. Probably because he knows Bruce and it just never occurred to him that Bruce might not know him. 

"I'm Tony. Tony Stark," Tony replies in his gentlest voice, "I'm your... friend." 

Bruce looks at him hard for a second, as if he's trying to remember who Tony is, and Tony thinks for a second that maybe he does remember him before Bruce shakes his head. 

"I've never met you," Bruce says as he rubs his face on his sleeve again. "But you've met me?" 

"Yeah, it's a little complicated," Tony replies, ignoring the way his stomach drops at the idea of Bruce forgetting about him for good if this is never sorted out - which won't happen, because they are going to sort this out. 

"Where's mama?" Bruce asks next, looking very worried. 

"She's - um, she's okay," Tony mumbles, not sure what to say to that. Though young Bruce doesn't know it yet, his mother was killed by his father many, many years ago. Tony's throat feels tight as he comes up for an excuse as to why Bruce is currently parentless in the house of a stranger. "She had to go away for a bit and you're going to stay here with me for a while." 

Bruce looks unconvinced, but he doesn't ask any more questions, only sinking down in his seat a little. Tony hopes his little lie with suffice to keep Bruce from freaking out about the whole situation. Pepper would be a lot better at this, he thinks. She'd know what to say. 

"Anyway, are you hungry at all? Thirsty? Like I said I've got this soy milk-" 

"May I have the milk?" Bruce asks politely in his soft little voice. 

"Sure, Bruce. Of course - let me go find a cup..." Tony says as he moves to open a nearby cabinet. He squints at all of the shining glasses inside for a moment, and almost grabs one before wondering if it's a bad idea to give a breakable glass like this to a child and closing the cabinet again. Instead he grabs his own Stark Industries mug and rinses out the coffee that stains the insides so that he can pour milk into it for Bruce. 

"Here," Tony says as he hands the mug to Bruce, who eagerly takes it and sips from it like he's never seen milk before. Tony wonders if all of that crying has dehydrated him. 

Tony watches Bruce drink for a moment before he glances across the countertop and spots his cell phone lying there. He slides it over to himself and immediately brings up his messages and starts sending out SOS texts to the rest of the Avengers (minus Thor, who's in Asgard), because he doesn't trust SHIELD to get shit done. 

_bruce has mysteriously been transformed into a five year old. HELP -TS_

He gets a reply back from Steve a minute later. 

_SHIELD already contacted me about an emergency, but I never expected it to be something like this! Sounds like you're going to need a lot of help catching the culprit. I'll be there as soon as possible. -SR_

And then a reply comes from Natasha. 

_Can't even take care of one of your own? I'll be right over to clean up your mess, Stark. - NR_

Tony sticks his tongue out at the phone and as he does it lights up again with a text from Clint. 

_sure ur not just drunk? -CB_

Tony rolls his eyes at that and shoots Clint a reply. 

_haha funny. i wouldn't get drunk this early in the morning. just get your ass over here, bird brain. -TS_

__

_like i havent heard that 1 b4 -CB_

Tony looks up to see Bruce watching him, mug still held tightly in his small hands and a white streak of milk on his lip. Tony opens his mouth to say something and someone else's voice comes out. 

"Oh my god." 

There's a crashing sound and Pepper's at the door with a hand over her mouth and her eyes wide with shock. Her purse is lying on floor where she dropped it and everything is silent except for the sound of her lipstick rolling away. Tony turns to her, his expression a mixture of relief and guilt and fear. She takes a few shuddery steps forward in her heels, her eyes on Bruce, who shrinks smaller into his chair. 

"Is that who I think it is?" Pepper gasps, clutching Tony's shoulder as he meets her in the middle of the kitchen. 

"Yeah. Yeah, it's Bruce. Bruce, this is Pepper, she's going to take care of you too." 

Bruce nods slowly at Tony's words. Pepper is speechless, now, and she walks past Tony to take a closer look at their de-aged partner. Bruce watches her with big brown eyes that contain much less fear than they had when Tony first encountered him. Tony doesn't know if this is a sign that he's remembering something or if he's just more afraid of men than he is of women, which would make sense considering what Tony knows of his childhood. 

"Bruce, how are you feeling?" Pepper asks, taking deep breaths and crossing her arms tightly over her chest as if she's trying to physically hold her emotions in to stop herself from panicking. Tony wishes that Bruce had roped them into a couple more of his meditation sessions before he got all tiny, because those would really come in handy right now. 

"'M okay," Bruce mumbles, and his cheeks turn pink again but this time he's not crying, he's actually blushing. Everything about his closed up, uncomfortable body language suggests that he's not used to being the center of attention like this. And then Pepper lets go of herself and looks overwhelmed and she wraps her arms around Bruce instead and Bruce doesn't resist, sinking into her embrace. They stay like that for a while as Tony watches and frets and wonders when SHIELD will show up so they can get this all sorted out. Then Pepper picks Bruce up and holds him close and asks Tony, all business again as she steels herself for the complicated task ahead, "Did you see him last night?" 

"We were working in the lab and I got tired and came to bed, but he said he needed a few more minutes to check things over. I was asleep before he came back, if he came back at all. The lab was a mess where I found him this morning." 

"Have you checked the security cameras in the lab?" Pepper asks as she begins to stroke Bruce's curly head, probably more to keep herself calm than to reassure him. 

"Uh. Actually, I was just about to do that when you walked in." 

"Then you'd better get back to work," Pepper orders sternly, "I'm going to get some clothes for Bruce so he's not walking around in just a shirt... Are you hungry?" The last part is directed towards Bruce, who nods a little, but Tony also answers weakly, "I want coffee." 

Pepper shoots him a glare but kisses him on the cheek as she leaves the kitchen with Bruce. "Check the security footage, Tony. And JARVIS, get some coffee brewing." 

"Yes ma'am," says JARVIS, and the coffee machine immediately starts up. Tony looks over at it with a sigh. Time to get to work. 

In a few short minutes Tony is standing in the middle of his violated lab, watching the security footage on a holographic screen while he sips his freshly-brewed coffee. A pixellated adult Bruce is currently wandering around the lab, a tablet in his hands as he checks his calculations. Bruce runs a hand through his thick curls in that way that drives Tony nuts, and Tony grins fondly to himself but feels a stab of pain is his gut because he should have been there, he should have stayed up with Bruce and then maybe he could have protected him. Together maybe they could have stopped this from happening, or at least Tony could have been the one being babied by Pepper while Bruce tried to fix the problem. Tony thinks he would have liked that better. Bruce probably would have a solution by now, anyway. He's brilliant. 

"How's the research going, Tony?" 

Steve's walking into the lab now, flanked by the two assassins. Natasha is scanning the room disapprovingly while Clint squints over at the broken window. Steve steps over some of the papers lying on the ground to stand just behind Tony and watch Bruce wander around on-screen. 

"It's going," Tony replies, "Watching security footage right now. And step back, Steve-o, you're looming." 

Steve steps to the side, smirking at the ground and putting his hands on his hips. On the screen, Bruce moves to organize some papers on the table that is currently lying on its side in the lab. Tony gets tense, knowing that the incident could happen any minute. And then it does happen, and Tony's jaw drops. There's no gunshot, no explosion, no light show. The window simply shatters behind Bruce, who shouts in pain and shock, dropping the papers everywhere. He clutches at the back of his neck, pulling something out in his fist, and Natasha (who just popped out of nowhere, how does she even do that?) whispers to Clint, "Go look for the projectile." He darts off to the overturned table immediately. 

Tony watches closely as Bruce's whole body trembles, and then he slumps into the table, knocking it over and falling to the ground behind it. He's obscured from view but Tony can hear his pained moaning, which turns into small panicked whimpers when a much smaller Bruce peeks his head out from behind the table. Steve gives a small gasp, which probably wouldn't even be audible if he wasn't still looming over Tony's shoulder like that. Tony watches the tiny Bruce pull the purple shirt on and stumble around the lab, accidentally knocking over a few things in the process, and then begin to cry and return to huddling behind the table. Tony fast-forwards until he sees himself walk on-screen, and then he shuts it off and turns to Steve and Natasha. 

"So," Tony recaps, "Bruce was just doing sciencey-business in the lab, being a big genius and all like always, when some asshole decided to shoot him with a thingy and turn him into a messy little kid who's, frankly, too adorable to be mad at for dropping shit all over my lab." 

"In his defense, your lab always looks like this," Natasha quips, smirking at Tony. 

Tony's about to give her a smartass retort but Clint interrupts him with, "I found the thingy." 

They all crowd the table immediately to see just what the "thingy" is, and Clint presents them with a strange little projectile that looks sort of like a high-tech tranquilizer dart. There's no liquid in it, as Bruce obviously wasn't able to pull it out of his neck before it emptied its contents into his bloodstream. 

"This would have to be shot from the air to be able to break the window like it did," Clint determines as he inspects the object in his gloved fingers, "The other buildings are all too far away for someone to get such an accurate shot with enough force to shatter it. Unless they were me, of course." 

Clint grins and Natasha rolls her eyes and crouches down to take the projectile from her partner and slip it into a plastic baggie to keep as evidence. 

"So... We're looking for a baby-snatcher on a hoverboard?" Tony asks. 

"They were most likely in a ship or something. But a hoverboard would be way cool," Clint replies as he stands up and looks out the window with a small grin. 

"The big question is, why did they want to change Bruce into a child?" Steve says, crossing his arms. 

"They probably wanted to neutralize The Hulk," Natasha suggests as she rolls up the projectile in the baggie and puts it in a pouch at her waist. 

"By turning him pint-sized?" Tony asks, and then it strikes him that maybe Bruce might not be The Hulk at all anymore. What if this de-aging reversed the effects? What if - 

"I wonder if Bruce can still transform. Maybe their motive was to remove The Hulk completely, and turning him into a child was the only way to remove the effects of gamma radiation?" Steve offers, and Tony frowns because hey, he thought of that first. 

"You don't really know how science works, Spangly. Even if Bruce is tiny now, the gamma radiation should still be in his blood unless his cardiovascular system underwent a complete overhaul," Tony argues, "Then again, I'm not the authority on gamma radiation, he is. Hey, is Selvig in town? He might know what to do. I'll give him Bruce's gamma radiation notes, and he can do some research while we take down the bad guy and find the antidote before anyone else gets baby-fied." 

"Not so fast, Tony," says Pepper as she enters the lab, Bruce on her hip. Clint immediately lets out a "D'aaaaw," while Natasha smiles sympathetically at the sight of what's become of their teammate. Steve stays serious, but his eyes are soft as he looks at the miniaturized Dr. Banner. 

"You're not leaving me here to take care of Bruce alone," Pepper tells Tony. "I'm sure Steve, Natasha, and Clint can handle the mission without you." 

"But _Pepper_ ," Tony whines as he turns to look at her and Bruce. Then he gasps, because apparently Pepper thought it was a good idea to put Bruce in a little hoodie with teddy bear ears on it. 

“Oh my god, what is he wearing?” 

"We just went to the closest kid's clothes store," Pepper sighs, exasperated, "You can't tell me you don't think it's cute. Even Happy was able to spare a smile when he saw it." 

"I'm not saying it's not cute, it's fucking adorable," Tony says, shaking his head, "But teddy bear ears? Really?" 

"Come on, Tony. Everyone already knows you call Bruce your teddy bear in bed," Pepper teases with a smirk. 

"Oh my god. Is that true?" Clint asks, grinning from ear to ear. 

Tony sticks his tongue out at Clint and walks up to Pepper and Bruce instead. "Did he get something to eat?" Tony asks her, and she nods in reply. 

"Happy and I went by the clothing store and then picked up McDonald's for him. The whole time he kept telling us that he wanted to get back to the tower because your promised to do science with him," Pepper explains pointedly. 

"Right. Science, kiddo," Tony says as he reaches over to ruffle Bruce's hair under the bear-hood. 

The rest of the team starts to leave and Tony makes pleading eyes at them but they don't seem to be in any mood to argue with Pepper. Natasha touches Pepper's shoulder lightly and breathes, "Good luck." 

Pepper smiles at her and says, "I'm going to need it. Tony is enough like a child himself already. And now Bruce..." 

Natasha nods sympathetically and promises, "We'll find the cure soon." 

"Keep me posted!" Tony calls after his departing teammates, and then he turns to Pepper and Bruce with a pout. "What do we do now?" 

"Well," Pepper begins thoughtfully, "You're going to take care of Bruce - do that science you promised, perhaps? - because I need to go out again." 

"But I thought you said we'd take care of him together," Tony whines. 

Pepper shifts Bruce into one arm in order to put the other on her hip. "Unlike _you_ , Mr. Stark , I can't just drop everything and stay home. I have to settle some business matters before I can join you. It's called a _job_ , Tony, have you ever heard of it?" 

"But you work for me," Tony complains, "Can't I just give you the day off?" 

"Wishful thinking, Tony. Without me to sort things out your whole company would fall to ruins in a day. Are you afraid of taking care of Bruce on your own? Are you saying that Iron Man can't handle a tiny five-year-old?" 

Tony gives her a look of feigned apprehension. "Does he bite?" he quips, and Pepper rolls her eyes. 

"You'll do just fine." 

She lowers Bruce to the ground and it still amazes Tony that a man who'd seemed so substantial to him now barely reaches his knee. Bruce clings to Pepper's leg with one hand, the other wrapped around a little green toy that Tony supposes was from the Happy Meal. Bruce looks up at Tony through glasses that are still much too large for his face, and Tony wonders if Pepper has ordered a smaller pair for him already or not. She probably has. Pepper always thinks of everything. 

Tony crouches down and extends a hand to his tiny partner. 

"Shall we play?" 

\--------------- 

Tony takes Bruce to the side of the lab that was unaffected by the night's events. Dummy and Butterfingers are currently cleaning up the leftover mess, avoiding the corner where the incident occurred in case there is more evidence to be found. 

"Are those robots your pets?" Bruce asks as he watches the two robots pick things up. He's holding Tony's hand, his fragile little fingers entwined with Tony's rough, calloused digits. 

"Sorta. They're kinda like my assistants. I made 'em." 

"You _made_ them?" Bruce gasps in awe, mouth agape. 

"Yeah, it's not such a big deal. They suck at following orders. Anyway, what do you want to do?" Tony asks as he leads Bruce toward an empty table with some stools around it and mechanical plans spread atop it. Bruce continues to watch the robots in wide-eyed wonder as Tony picks him up and deposits him on a stool, then clears off the table for... whatever they're about to do. Kiddie science, right? 

"You said we'd grow lima beans," Bruce reminds him softly, not taking his eyes off the robots. 

Tony nods and says, "Okay, JARVIS, keep an eye on Bruce while I go get supplies." 

"Yes, sir." 

Bruce looks up, startled, at the sound of JARVIS's voice. Tony notices and grins. "That's JARVIS. Just A Really Very Intelligent System. I made him, too, and unlike Dummy and Butterfingers he's really great at following orders." Seeing the way Bruce is looking around the room for a source, he adds, "You can't see him. His voice comes through hidden speakers." 

Bruce nods slowly, taking this in. "I heard you talking to him before. May I try?" 

"Sure, buddy. Just say his name before you ask him something and he'll answer whatever questions you have. I'll be right back." 

When Tony returns with the beans and cups and paper towels, Bruce is deep in a conversation with JARVIS. 

"How did Tony make you?" he's saying, and Tony stops in the doorway to listen to what JARVIS' response will be. 

"Mister Stark is very good with computers. He created the very complex codes that form the basis of my interactions with human beings." 

"Tony must be really smart, to do all that," Bruce says, obvious awe in his voice. In the doorway where he stands, Tony smiles. 

"Mister Stark is indeed a genius." 

Bruce suddenly saddens, looking down at his hands on the table. 

"Mama says I'm a genius. But father... He thinks that's bad." The hand he's looking at curls into a fist on the table and Tony sees his brow furrow in frustration. 

Tony's chest aches at the sight and he decides that now would be a good time to intervene. He walks into the room and interrupts, "Hey, Bruce." 

Bruce lays his hand flat and looks over at Tony with the sad gaze of a guilty puppy. "H-Hi." 

"Hey, it's okay. I got the stuff for the experiment. Did JARVIS take good care of you?" 

"I like JARVIS," Bruce says with a nod. He looks at all of the things that Tony lays on the table but doesn't touch them, courteously keeping his hands to himself in a way that Tony's never been good at. 

"Yeah, he's pretty cool," Tony says, nodding in agreement. He holds up one of the lima beans and squints at it. "Anyway, we're gonna plant these without any dirt. It's supposed to teach kids about how plants grow and shit. I remember doing it in science class when I was little." 

"Was it fun?" Bruce asks. 

"Uh... Well, mine died. But that's beside the point," Tony chuckles, leaning against the table and rubbing the side of his face. "I'm sure these won't die if someone as smart as you is planting them." 

Bruce blushes as he looks down at his hands again. "'M not that smart." 

"Don't be shy about it, Bruce. You're brilliant. The smartest man I know," Tony says with an encouraging smile. "You know what? I think you might even be smart enough to make a robot. Maybe we can do that after the beans - that is, if you can keep them from dying." 

Bruce brightens immediately, nodding with the most enthusiasm he's shown all day. "I won't let them die, Tony!" 

Tony grins widely and places the beans into Bruce's eager hand. "Alright, first you have to fold them up in the paper towels. Once you've done that we'll go on to the next step." 

Bruce nods and does as he's told, folding the paper towel into a very neat square. He's very careful, all of his actions controlled and precise, and it's no wonder that he'll grow up to do surgery and handle delicate lab equipment. 

"Aren't you going to plant one, Tony?" Bruce asks. 

"Nah, I might kill it again," Tony says and shrugs. 

"I could help you," Bruce offers. 

Tony laughs and says, "Yeah, sure, I'll plant one, then. You're going to have to take care of it, though. There's a reason I only keep robots. I can never remember to water the plants Pepper brings home..." 

"I will," Bruce promises. He pushes some of the beans and a paper towel over to Tony, and watches him expectantly while he folds them up into a much messier square, and although Bruce doesn't say anything Tony can see him wrinkle his nose at the half-assed job. Tony dictates what to do next and the two of them put their paper towels into cups and then hydrate them with water from a plastic bottle that Tony brought along. Tony tells Bruce to go put them in a place where they'll get sunlight and Bruce hops down from the stool with the two cups wrapped tight in his arms and he carefully walks them to the nearest window. Tony observes Bruce discreetly straightening out the uneven edges of Tony's damp paper towel and Tony laughs because that's _so_ something Bruce would do, and he instantly realizes how much he misses Bruce - not the child before him, but the graying, sarcastic doctor that he fell in love with. Who knows when he'll see him again? With Pepper forcing Tony to stay home, how long will it take his three remaining teammates to find a cure, if there even is one? He suddenly has the urge to go over to his bar and grab a drink, anything to soothe his troubled mind. 

"Tony?" Bruce asks him and breaks him out of his reverie. The tiny kid's watching him through those enormous glasses with a look that's beyond his years. 

"Mm?" Tony mumbles, rubbing his forehead for a moment before giving Bruce his full attention. 

"Can we make a robot now?" 

"Sure, buddy. Whatever you want." 

\---------------

When Pepper returns, Tony and Bruce are sitting on the floor of the lab, mechanical parts and pieces scattered around them as they work diligently on a small robot. In the planning stage Bruce had requested that the robot be useful, not just a toy, so together they had decided that the 'bot would be able to unlock a door when a special password was said. The idea had appealed to Bruce immensely, and they had gotten straight to work. It isn't anywhere near being finished yet but both Bruce and Tony are already very proud of their creation. 

"Hey, boys. What are you making?" Pepper asks in an almost too-cheerful voice as she walks in, as if she's trying to distract from how weird this all is. 

"We're making a robot, Pepper," Bruce says happily, looking up and smiling as she approaches. Tony rises immediately and practically skips over to her and kisses her on the lips before enveloping her in a hug. 

"Miss me that much?" Pepper laughs, and Tony nods into her neck. 

"WhatarewegoingtodoPepper," he groans. 

"I thought we'd order pizza," Pepper says as she pats him on the head, "I don't want to take Bruce out of the house again, it'll just confuse him more... And since he can't exactly cook for us..." 

Ever since Bruce came to live with them he has made a habit of cooking dinner every few days, whenever he is bored or when Pepper and Tony beg him. (Or rather, when Tony begs him - Pepper doesn’t _beg_ but she has a _way_ of always getting what she wants.) He's the only one out of the three of them who can cook worth a damn, and they appreciate every meal he makes. 

"Yeah, pizza sounds good," Tony agrees as he finally lets go of Pepper, turning to see that Bruce is now standing as well, hovering over by the robot parts looking a little lost. Pepper smiles gently at him and says, "Hi, Bruce. We're going to order pizza. What topping would you like?" 

"I don't care," Bruce says shyly, looking down at his socks. 

"No, it's fine, Bruce, tell us what you want and we'll get it. It's no trouble." 

Bruce looks up at Pepper with his big brown eyes and replies, "I like olives." 

Tony and Pepper exchange a glance because they both knew exactly what he was going to say. Bruce loves olive pizza. 

"Then we'll get you olives, Bruce," Pepper says with a smile. "JARVIS?" 

"Yes, ma'am?" 

"We need some pizzas, please." 

"Which kinds?" 

"The usual," says Pepper, and then she pauses and narrows her eyes over at Bruce's small form before amending, "Except, make the olive a small." 

"Right away, ma'am." 

"Hey, Pepper, Bruce wants to show you the beans we planted," Tony says, winking at Bruce, who nods with a smile. 

"You're growing plants?" Pepper asks, surprised. She throws Tony a smirk. "Don't kill these like you killed the roses." 

"Okay, the roses were a freak accident," Tony grumbles, "You shouldn't have left them in the lab." 

"I left them in the lab so you'd remember to water them," Pepper says, rolling her eyes, "I didn't expect that you'd set them on fire first." 

"Like I said, freak accident," Tony dismisses the topic with a shrug, "Anyway, these can't die because Bruce is taking care of them and Bruce is a very dedicated scientist. Right, buddy?" 

"Mhm!" Bruce nods and waves for Pepper to follow him to the window. "I'll show you!" 

Pepper smiles at Tony and begins to walk over to Bruce, hissing over her shoulder, "Call Selvig! I didn't get a chance to while I was out." 

"Oh, right!" Tony slaps himself on the forehead and slides his cell out of his pocket. He'd rather not call Selvig through the speakers and let Bruce hear that they have to conduct some experiments on him. While Pepper looks at the beans with Bruce, Tony slips out into the hallway and tells his phone, "Dial Dr. Selvig." 

\---------------

Turns out Selvig is only a night's flight away and very eager to visit and run a couple tests on his pint-sized former colleague. 

"He'll be here sometime tomorrow afternoon," Tony tells Pepper as they wait outside the hall bathroom for Bruce to finish using the toilet and washing his hands before they eat. 

"That's wonderful," Pepper says with obvious relief, "Maybe he'll be able to shed some light on the situation." 

"I sincerely hope so. I also called up the team and they say they haven't caught anyone yet, but," and Tony changes his tone to mock Steve's earnest _Captain-America-to-the-rescue_ voice, "We've found a couple of clues that should help us track the bad guy down in no time." 

"They'll manage fine on their own," Pepper laughs. Bruce emerges from the bathroom a moment later, wringing together hands that are still damp from washing and looking up at Pepper and Tony questioningly. 

"You can go wait in the kitchen while we wash our hands, Bruce. First door to the left. Pizza will be here any minute,” Pepper instructs gently, and Bruce nods and pads off as Tony and Pepper enter the bathroom together. 

"Oh my god, look at us,” Tony says incredulously as he turns on the sink, “We're so _domestic_ ." 

"We really are, aren't we?" Pepper laughs as she runs her hands under the water, "Looks like you’re getting along with Bruce really well. He seems to have opened up a lot while I was gone. I had no idea you're so good with kids." 

"I'm not - or, at least, I think I'm not,” Tony says as she steps aside to dry her hands and he sticks his own into the sink, “I dunno, this is different. I mean, it's _Bruce_ . I kinda already know him. But really, this kid's a fucking genius. I think he understood more about the internal workings of that robot we're building than you. And he's, like, _five_ ." 

"No need to _rub it in_ , Tony." 

When they meet Bruce in the kitchen he's sitting at the table already and they sit down with him and wait for JARVIS to tell them that the pizza's arrived. Pepper _persuades_ Tony to go get it from the tower lobby because it's late and all of Pepper's assistants have gone home already. When he comes back with the pizza Pepper's gotten an iced tea for herself and a can of lemonade for Bruce, and she has to _persuade_ Tony to get a coke instead of a scotch, because she says Bruce is small and impressionable and Tony should be setting a good example for him. Tony tries to tell her that that's ridiculous, he won't be small forever, but Pepper reminds him in his ear that Bruce's father was an alcoholic and the color drains from Tony's face and he shuts up and drinks his coke. The last thing he wants is for Bruce to think that Tony is anything like his father. 

As Pepper passes Bruce a slice of olive pizza on a plate he thanks her and then asks in a small, anxious voice, "When will I be going home?" 

"What, are we not fun enough?" Tony jokes in mock-offense. 

"No! No, I mean, yes, you're fun! It's just..." Bruce trails off, and then finishes in a trembling mumble that’s barely above a whisper, "'M just worried about mama." 

Pepper and Tony exchange anxious glances before Pepper explains sympathetically, "We're really sorry, but we’re not sure when you'll get home, Bruce. But we promise we'll do everything we can to get you back soon." 

"Yeah, don't worry, Bruce," Tony agrees. "Everything will be back to normal in no time." 

"Okay," Bruce says, not sounding nearly as confident as them but at least satisfied with the answer. He plucks at a bubble in the pizza crust, popping it with his fingers. 

Pepper and Tony look at each other again, and then Pepper's face lights up in realization. 

"Oh, Bruce! I just remembered, I got you glasses in your size," Pepper says, effectively changing the topic, and fishes a small glasses case from her purse. She hands it to Bruce and he accepts it with a small 'Thanks' before snapping it open and examining its contents. 

"Well, let's see 'em, champ," Tony says with a grin. Bruce nods slowly, apparently still wary of the gift, and exchanges his ill-fitting adult-sized glasses for the child-sized ones. He looks up at the two across from him once they're sitting snugly on his nose and they both smile. 

"They look great, Bruce," Pepper tells him, and he blushes slightly, looking down at the pizza slice on his plate. 

"They do! You look like even more of a genius now," Tony says, clapping his hands together so loudly that Bruce jumps a little. "Pepper, pass me a slice of pepperoni..." 

While they eat, Pepper tells Bruce stories of how Tony has killed roses and carnations and even cacti in the past, and that's why they now stick to statues and robots instead of living things. She gets Bruce to laugh and Tony can't help but smile because he's never seen a look so purely innocent on the face of the adult Bruce Banner he knows. He assumes that the small Bruce before him has yet to experience most of the emotional trauma that Tony knows is yet to come. Judging by his earlier interaction with JARVIS, Bruce has already met his father's bad side, but it seems like, at this young age, he hasn't seen the worst of it. It makes Tony really fucking sad to think that this sweet little kid is going to have to go through so much suffering in order to become the man he loves. He wishes he could prevent all the pain and then he starts thinking - what if he _could?_

"Are you okay, Tony?" Pepper asks him softly, nudging him with her shoulder. He must have zoned out. Pepper and Bruce are both finished eating by now. 

"Yeah, yeah, it's nothing," Tony says, waving it off, but Pepper quirks an eyebrow, unconvinced, and Tony sighs. "I'll tell you later." 

Pepper's eyes drop to Tony's shirt and she frowns. "You've got sauce on you. And oil, for that matter." 

"Oh?" Tony says, and looks down to find a bright red sauce stain surrounded by specks of black grease from the lab scattered across the white tank he's been wearing all day. He smirks over at Bruce and asks, "Did you see that happen? I didn't." Bruce shakes his head with a small giggle, and Tony just shrugs and peels the shirt off over his head. This elicits a gasp from Bruce, and Tony tosses the shirt aside to see him gawking at the arc reactor. 

"What's that, Tony?" he asks, making a supreme effort to hide the horror in his voice. 

"Wait -" Tony laughs in confusion, "You didn't - it's been there the whole time!" 

"I thought it was part of the shirt," Bruce mumbles, sinking down in his seat a little in embarrassment. 

Tony continues to laugh and Pepper slaps him lightly on the shoulder, but he sees her smiling as well, albeit a bit sympathetically. 

"Bruce, that's the arc reactor," Pepper tries to explain, "It -" 

"It powers an electromagnet that keeps a bunch of deadly shrapnel from reaching my heart. I made it after a bunch of terrorists tried to blow me up," Tony tells him easily. He usually doesn't like to talk about the reactor's origin, but, like when they met on the Helicarrier, Tony feels completely comfortable telling Bruce about it. 

Bruce, on the other hand, doesn't look comfortable at all - he looks absolutely terrified. Pepper sees this and glares at Tony. "You didn't have to tell him all that!" she scolds. 

"What? He's a smart kid, I didn't want to give him some bullshit about me being afraid of the dark or something." 

Then Bruce pipes up in a voice high-pitched with fear and worry, "Are... Are you gonna die, Tony?" 

"No!" says Tony, and at the same time Pepper hisses, " _See?_ ," and then turns to Bruce and tells him, "He's fine, Bruce. Don't worry." 

"Yeah, I wouldn't trust my life to some faulty Hammer tech. This is Stark-made. My own _ingenious_ design. It'll keep me going for a long time. Forever, even." 

"Oh," says Bruce, visibly relaxing now that he's sure that Tony isn't going to drop dead any second. And then his childish curiosity gets the better of him, and he asks, "Can I touch it?" 

Tony laughs and says, "Of course you can, Bruce." At the invitation, Bruce slides around the circular booth and Tony pulls him in close. 

"Here, clean your hands off first," Pepper suggests, offering Bruce a napkin. "If Tony gets the arc reactor dirty he can't just pull it off and throw it on the floor, he'll actually have to clean the sauce off." 

"Or you could just lick it off," Tony teases with a suggestive grin, and Pepper slaps his shoulder again with the hint of a blush on her freckled cheeks. 

Bruce puts his tiny hands on the arc reactor and marvels in its glow while Tony tells him how it works, because, hey, why not. The kid's brilliant. Unlike any other five-year-old, he seems to really understand what Tony's saying. He's not just nodding along, he's really absorbing everything he's told and asking questions that have a clear direction and purpose to them. Once he's satisfied his appetite for knowledge, Pepper drags him away from Tony to get him ready for bed, leaving Tony to reluctantly clean up the dinner mess. They return just as Tony is stowing the leftover pizza in the freezer. Bruce is now out of his teddy bear hoodie and wearing a t-shirt and pajama pants with dinosaurs on them. Pepper holds his hand, still in her clothes. 

"I told him he could sleep in the spare room next to ours," Pepper tells Tony, and then she looks down at Bruce and asks, "Would you like us to tuck you in?" 

Bruce shrugs a little and says, "I guess." 

Tony smiles and follows them to see Bruce off to bed. The guest room is more modestly furnished than other rooms of the tower but still impeccably stylish and modern. Bruce looks so small lying the middle of the king-sized bed they put him in, but they have no choice - they didn't expect to have any kids in sleeping over when they designed it. 

Pepper settles on the side of the bed and gently takes Bruce's glasses off his face, depositing them on the nightstand. Tony sits on the other side, fluffing up the pillows around the child's head. 

"This room's good, Bruce. It's got its own bathroom and it even has the _nice_ sheets. Plus, it's right next to us," Tony explains as he pulls the covers up to Bruce's chest. 

"If you need anything go right ahead and knock on our door," Pepper adds, running a hand through Bruce's curls before leaning over him to kiss him on the forehead. He looks a little embarrassed but only manages to mumble a small "Thanks" as Pepper stands. 

"I think she kisses you more than me," Tony whispers to Bruce, who giggles a little. Tony then also kisses him on the forehead, his beard scratching against the child's soft skin. 

"Sweet dreams," Pepper tells Bruce as Tony meets her at the door. Tony gets one last look at tiny, forlorn Bruce before Pepper shuts off the lights and closes the door. 

Pepper and Tony go right into their room to change and sleep as well. Tony usually would stay up for at least a few more hours but the confusion of the day had left him exhausted. Taking care of a kid is harder than it looks, even a well-behaved one like Bruce. 

Tony goes right to shower and when he emerges, hair damp and a towel draped around his waist, Pepper is already sitting cross-legged on the bed in her pajamas. 

“What is Selvig going to do to Bruce tomorrow?” Pepper asks as Tony pulls on his boxers. 

“He’ll take a blood sample and test it,” Tony explains, “We need to see if he’s still got gamma radiation in him.” 

“Right,” Pepper replies, “And if he doesn’t, that means no Hulk.” 

“Exactly. That’s what I was thinking about earlier.” 

Pepper’s quiet as Tony crawls into bed next to her, sliding under the covers. He snaps the room lights off and stares up at the ceiling as illuminated by the glow of the reactor in his bare chest. 

“If the Hulk's gone..." Tony ponders aloud, "Do you think Bruce would _want_ us to change him back? I mean... He's tried to get rid of him for so long, and if this is the only way..." 

It's just a thought - it’s not like they _aren’t_ going to change him back when they find the cure. Of course they are. They need him, the adult Dr. Bruce Banner, and they need the Hulk too, whether Bruce likes it or not. But it doesn’t stop Tony from thinking, wondering. 

“I think he would,” Pepper says finally, breaking him out of his thoughts, “He’s finally coming to terms with the Other Guy, you know. He knows how to coexist with him now, and together they’re doing a lot of good.” 

“I guess you’re right,” Tony agrees, and it’s no surprise because Pepper is _always_ right. But he can't get this other thought out of his head, so he goes ahead and says it. 

“But - do you think, even if the Hulk isn't gone... That he would maybe want us to, like, raise him?" Tony asks. The idea is absolutely ridiculous and Tony knows it, but he can’t help but think it. He knows and _understands_ better than anyone else how terrible Bruce's childhood was and he wishes he could just prevent Bruce from ever experiencing it. He also wishes Pepper wouldn't laugh because he really is serious about this but she does. 

"Tony," Pepper says, becoming serious under Tony's somber glare, "Are you saying you want to raise a child?" 

"All _I'm_ saying is I wish I could give Bruce a better childhood," Tony grumbles. Then he gets defensive and accuses: "Are _you_ saying I wouldn't make a good parent?" 

"No, I..." 

The small sound of a hand knocking on the door interrupts Pepper’s speech. Both adults look over at it in confusion and surprise, and when it continues Pepper asks tentatively, "Bruce? Is something wrong?" 

"Pepper? Tony?" Bruce's voice replies from the other side of the door, voice weak and trembling. 

Tony moves to get up but Pepper makes it to the door before he can even get his legs out of the bed. She opens the door for Bruce and in the light that filters in from the hallway Tony can see that his eyes are red and wet like he's been crying. 

"Are you alright, Bruce?" Pepper asks, kneeling down to look him in his puffy brown eyes. 

"I-I had a nightmare," Bruce mumbles, and then adds under his breath, "Green." 

Pepper shoots a helpless look over her shoulder at Tony, and Tony says, "Bruce, come here." 

Pepper brings the sniffling child to the bed, picking him up and placing him next to Tony, who's now sitting up against the headboard. Bruce leans back against it as well, curling his skinny knees to his chest. His watery eyes fall on the arc reactor, the only light source in the dark room. 

"Bruce, listen," Tony tells Bruce gently, "I have nightmares too. Even Pepper has them, sometimes, and she's the sanest person I know. But no matter how bad they are, you always wake up. Always." 

Pepper sits in bed beside Bruce, running her hand through his hair soothingly while he listens to Tony speak and peeks up from his knees to meet Tony's eyes as the arc reactor reflects its light in them. He looks back down at the light source again when Tony's finished speaking, staying quiet for a moment to take in what he's said. 

"Does the arc reactor give you nightmares?" Bruce asks, still eying it. 

"It used to," Tony admits softly, "But now I'm just happy that it's there, because... it means that I am, too." 

They sit in silence for a minute more while Bruce wipes his eyes on the fabric on his knees before asking in a quiet, breaking voice, "Can I sleep here?" 

"Of course you can, Bruce," Tony says with a warm smile. Pepper nods in agreement. 

"Here, you can sleep right between us," Pepper says, gesturing to the space between their two pillows. She gets up to grab a third one for Bruce but by the time she gets back the child has already snuggled himself into Tony's chest, head buried against his clavicle and small fists curled over the arc reactor. Pepper smiles softly as she pulls the covers over herself and her bedmates, sliding in close to lie an arm across them both. As she does, she strokes Tony's shoulder to get his attention and he looks over at her, eyes sparkling with more than just the arc reactor's glow. 

"I think you'd make a great parent," Pepper whispers to him as Bruce drifts off to sleep between them. 


	2. Chapter 2

**Summary for the Chapter:**

> Bruce is turned into a five-year-old by a mysterious villain and Pepper and Tony have to take care of him while the other Avengers track down the culprit.

When Tony wakes up, Bruce isn't there. He looks across at Pepper, who has her fingers entangled with his over the empty space where Bruce had been sleeping between them, and wonders how he even managed to get away. Tony carefully removes his fingers so as to not wake Pepper and sits up in a mild state of panic when it hits him that Bruce could be _anywhere_. He's so small and fragile and who _knows_ how much trouble he could have already gotten into. Or worse - how much trouble someone else could be putting him in while he is young and vulnerable.

"Shit, shit, shit," Tony mutters under his breath as he gets out of bed, pulls on a t-shirt and jeans, and hurries out of the room. 

He checks the room next door, but Bruce is nowhere to be found. He heads to the kitchen and finds it empty as well. The lab is next, and when he enters it he calls, "Bruce?" 

"Oh- um, hi, Tony," Bruce replies, turning around to wave shyly at him from where he's standing by the window, still in his pajamas. 

"Oh, thank god you're here," Tony sighs in relief. "You shouldn't disappear like that, you scared me." 

"I'm sorry," Bruce says, looking sheepishly at the ground as his fingers play with the edge of his shirt. "I- I didn't mean to scare you. I just wanted to check on the lima beans." 

"It's okay, Bruce," Tony says, relaxing as he meets Bruce by the window. "How are they doing?" 

"They grew!" Bruce says excitedly as he holds up one of the cups, which houses beans with tiny green tendrils peeking out of them. "Look, Tony, they sprouted." 

"That's great, Bruce!" Tony congratulates him with a wide grin. "Mine never even got that far. I over-watered them, I think." 

"Over-watered?" Bruce repeats worriedly. "I'll only water them a little, then." 

"Well you don't want them to get too dry, either," Tony reminds him. "How about you water them a little bit now, and then later you come back and give them some more? That way they'll have time to absorb." 

Bruce nods very seriously. "Okay, I'll do that." 

He switches the cup he's holding for the other, and looks inside it disapprovingly before holding it out to Tony. 

"This one's yours. It didn't grow as much as mine did, but don't worry. I'll make sure it lives." 

Tony laughs. "Okay, Bruce. I trust you." 

Bruce places the cup next to its fellow on the windowsill, then turns around again. "Tony?" 

"Yeah?" 

"How does photosynthesis work?" 

Tony quirks an eyebrow, shrugging. "Eh, air, water, sunlight, et cetera. I can't remember all the details, it's too early in the morning for thinking." 

"That's what they tell me at school," Bruce says, frustrated. "There's got to be more to it than just a bunch of ingredients. Isn't this experiment supposed to teach me how it works?" 

"The experiment doesn't teach you, it just _shows_ you. If you were in school then your teacher would explain it." 

"Can you be my teacher?" Bruce asks promptly. 

"I wouldn't make a very good teacher," Tony responds, running a hand through his hair. "Besides, Biology's boring." 

"I like Biology," objects Bruce, and then balls his hands into fists at his sides and grumbles,"I want to learn about it, but father won't let me read any smart books." 

Tony's quiet for a moment at that, then he says: "Hey, I have an idea! Why don't you ask JAVIS to be your teacher? He knows everything about everything." 

Bruce brightens immediately at the suggestion. "JARVIS, can you teach me about photosynthesis?" 

"Of course, Master Banner." 

Tony smiles, proud of his AI's efficient adaptability and functionality. He's already realized that the former Dr. Banner is no longer a doctor and has changed his name on his own. He listens to JARVIS' detailed explanation of the process for a while without really hearing anything that he's saying. He needs coffee before his brain will function correctly, and he decides to slip away and go get some while Bruce is occupied with JARVIS' lesson. 

\---------------

Pepper is lured into the kitchen by the smell of coffee brewing. She finds Tony drinking out of a mug by the coffee maker and takes a cup of her own. 

"Where's Bruce?" she asks as she stirs in some creme. 

"He's in the lab, learning about photosynthesis from JARVIS," Tony explains between large gulps of coffee. 

"Eager to learn," Pepper observes with a nod, "That's good." 

They drink together for a few more minutes before Pepper has to leave to get dressed for work. 

"You'll be fine taking care of Bruce all day, right?" she asks. 

"If I could handle him yesterday, I can handle him today," Tony replies confidently. 

"Good luck," Pepper says anyway, giving him a quick peck on the lips before heading out. She tastes like coffee, which makes Tony suddenly crave it again and he refills his mug before heading back to the lab to check on Bruce. 

\---------------

Bruce is sitting in a chair when Tony returns, staring attentively at a holographic model of a plant cell that JARVIS has conjured up for him to inspect. 

“Hey, how’s the lesson going?” Tony asks, placing his coffee down on the table and stepping back to look at the hologram with Bruce. 

“It’s great!” Bruce says with a big smile. “Look, Tony, this is a plant cell, it has a cell wall and chloroplasts and everything!” 

“That’s neat. Did you know you can touch these holograms?” Tony asks. Bruce shakes his head and Tony leans past him to pick up the cell easily. Bruce’s mouth opens in a gasp and he demands eagerly, “Teach me!” 

Tony shows him how to manipulate it in his hands, first placing the hologram into Bruce’s open palms and letting him look at it from all angles before showing him how to select and grab it from the interface himself. 

Eventually JARVIS announces that Selvig has arrived and Tony tells the AI to let him in. The door opens instantly and Selvig walks in, dressed in a casual button-down and slacks and carrying a case that is presumably full of his own lab equipment. 

"Dr. Selvig!" Tony exclaims with a grin as he turns to see him. Bruce accidentally drops the holographic plant cell in surprise, his eyes wide as he looks at the newcomer. 

"Mr. Stark!" Selvig replies, laughing, as Tony walks up to shake his hand. "Is that my old colleague over there?" 

"Not so old anymore," Tony quips as he nods. Selvig releases his hand and walks over to the table where Bruce is sitting. 

"Bruce Banner?" Selvig asks, bending his knees slightly to get down to the kid's level. He holds out a hand, and Bruce glances over at Tony for approval - which he receives in a smile and a nod - before shaking hands with the doctor. 

"I'm Dr. Selvig," he explains, "I'm going to be running a couple of tests on you today, but don't worry, it's nothing serious." 

"Am I sick?" Bruce asks, confused. 

"No, no," Selvig says, "I'm not even a medical doctor, so I'm not looking for any kind of sickness. We've just got to take some of your blood and see what kinds of chemicals you've got inside you." 

Bruce doesn't seem convinced at all, but he glances over at Tony again. 

"It's alright Bruce. How about we find you some clothes while Selvig gets all set up?" 

"Okay." 

Bruce hops off the chair and takes Tony's hand. JARVIS makes the plant cell model vanish into thin air, and Selvig opens his case onto the table in its stead. 

Tony takes Bruce to the guest room where they had thought he'd be staying before he'd decided to take up residence between Pepper and Tony. He knows Pepper put all of the clothes she bought Bruce there, and conveniently finds them in the first dresser drawer he opens. 

"Aha," he says, pulling out the shirt on the top of the folded stack inside and holding it up to see that it's - an Iron Man shirt? 

"Did Pepper buy you this, Bruce?" Tony asks, dumbfounded. 

"Yes," Bruce says as he fiddles with the edge of his pajama shirt again, "I _think_ she said you'd like it." 

"Of course she did." Tony glares at the red and gold t-shirt, which is designed to look like the front of the Iron Man suit itself. Bruce doesn't know who Iron Man is, let alone that Tony _is_ Iron Man. Pepper had clearly bought it just to mess with Tony. He sighs once before giving up and handing the shirt over to Bruce and finding him a pair of jeans to wear with it. 

Bruce changes into the day clothes and, after pulling on the shirt, looks down to run his fingers over the design, stopping when he hits the pale blue circle on his chest. 

"Hey, Tony," he says, "This looks like the arc reactor." 

"Uh, yeah, it kinda does," Tony says with a shrug. 

"That's weird," Bruce mutters, clearly confused by the similarity. 

"Yeah, it's pretty weird. But, hey, now we match," Tony says with a smile, taking Bruce's hand again and heading back to the lab. 

\---------------

Selvig is waiting for them when they return. He's brought with him the necessary tools to draw blood from Bruce and has everything already sanitized and ready for use. 

"Hey, Bruce," Selvig says with a smile, "Are you ready?" 

Bruce eyes the hypodermic needle on the table and shrinks back slightly, swallowing hard. After a moment's hesitation, he looks up at Tony. 

"Can Tony do it?" he asks. 

Tony looks over at Selvig, who shrugs. "It doesn't matter who takes it, I just need it," Selvig chuckles, "Tony, do you know how?" 

"Sure, yeah, I've taken blood before." He turns to Bruce. "Go sit down, buddy, I'll do it." 

Bruce looks a lot less nervous as he settles into the large chair. Tony strides past him to examine all the venipuncture tools that Selvig has laid out. 

"You're going to want to protect yourself, just in case," Selvig tells him quietly as he hands him a pair of safety gloves. Tony waves them away and shakes his head. 

"I've got my own." 

Tony and Bruce - when they were both adults - had done quite a lot to keep the lab and its inhabitants healthy and gamma-free. They installed radiation sensors all over the lab and created, among many other safeguards, gamma-resistant gloves. They were appropriately green in color and went all the way up to Tony's elbows as he pulled them on. 

"Did you make those?" Selvig asks, examining the flexible green material. 

"We did," Tony replies. 

"Have you done this before?" Selvig asks. 

"I have," Tony says, and he anticipates the follow-up question before it is asked. "He made me destroy all the samples, so you can't see them, sorry. But JARVIS kept all the data, just ask him about it." 

Selvig smiles. "Perfect. We'll have something to compare our new sample to. JARVIS? Get me the data on all previous Bruce Banner blood samples..." 

Tony turns to Bruce as Selvig crosses the room. He's got a stethoscope and a sphygmomanometer in one hand and a tray with the needle and vacutainer in the other. Bruce is busy tracing the lines of the Iron Man suit design on his shirt when Tony pulls up a chair next to him. He looks up at Tony, adjusting his glasses slightly and tilting his head. "Are we starting?" 

"Yep. I'm just gonna take your blood pressure first," Tony explains, placing all his tools on the table beside him before picking up the ones he needs. 

"Which arm do you want me to do it on?" Tony asks. 

"Umm... My left," Bruce decides, holding it out after a bit of consideration. Tony nods and slides his chair closer to wrap the cuff around the boy's thin upper arm and slide the stethoscope beneath it. He begins inflating the cuff, watching Bruce's face to make sure he isn't causing him any unnecessary discomfort. 

"Dr. Selvig is okay with you using all of his doctor stuff?" Bruce asks over the sound of air puffing into the cuff, a crease of worry forming on his brow. 

"Of course. I'm no doctor but I know how to take care of some tools. Don't worry about it." 

"JARVIS thought I was a doctor," Bruce tells Tony. "When I woke up here. He said Dr. Banner." 

Tony nods. "He was confused," he says, then chuckles, "We all were." 

He starts releasing air from the cuff, focusing on the sound of Bruce's blood flowing in his artery and telling JARVIS to keep track of the data as he speaks it out to him. He removes the cuff shortly afterward and places it aside, pulling the stethoscope out of his ears to let it rest around his neck. Bruce prods at the end of the stethoscope and asks, "Can I hold it?" 

"Sure, buddy," Tony says, pulling it off his neck and handing it to Bruce. He turns to the table to get the tourniquet and alcohol wipes, and when he looks back Bruce is wearing the stethoscope and Tony grins because it reminds him of older Bruce Banner, playing doctor for real in third world countries. 

Bruce sees Tony's grin and smiles back, giggling as he touches the end of the stethoscope to the front of his shirt and says, "I'm listening to the arc reactor." 

Tony laughs and reaches for Bruce's arm to tie the tourniquet. "The arc reactor actually just makes a sort of humming sound. Pepper says it's soothing. You can listen to the real deal when we're done taking your blood, if you want." 

"Okay," Bruce says with a small smile that quickly twitches into a frown at the tightness of the tourniquet. “Is this going to hurt?” 

“Uh... no,” Tony tries, searching with his eyes for a vein in Bruce’s outstretched arm. Bruce looks at him, a small smile on his lips. “You’re bad at lying.” 

“Okay, fine,” Tony chuckles, “It’ll hurt a tiny bit when it goes in, but that’s it. After it’s in you can barely feel it, I promise.” 

Bruce nods, apparently believing him this time, and bites his lip a bit as Tony rubs the alcohol wipe over his exposed vein. The needle goes in a second later, and Bruce flinches slightly but keeps his arm still under Tony’s green-gloved fingertips.. 

“See? That didn’t hurt, right?” Tony asks Bruce as dark blood starts to pour into the vacutainer. 

“N-No,” Bruce says, but Tony can see his free hand squeezing the end of the stethoscope as it rests against his stomach. 

“Just relax,” Tony says softly, “It’ll be over soon.” 

He fills a second vacutainer before carefully sliding the needle out of Bruce’s arm and immediately pressing a cotton ball to the oozing speck of blood left behind. 

“All done. Look, you get a purple bandage ‘cause it’s the only one we have,” Tony says with a smirk as he wraps the medical bandage around Bruce’s elbow, securing the cotton ball in place. 

Bruce watches him apply a bit of pressure to the spot and asks, “Will testing my blood help me get home?” 

“I hope so,” Tony says, turning away after a moment to dispose of the now-toxic needle safely. 

“I don’t even know how I got here,” Bruce says, frustration tightening his tone as he picks at the itchy edges of the bandage, “I just woke up in your lab.” 

Tony walks back over to him and sits down again. “Bruce, we’ll get you back home. I promise. Don’t worry about it.” He pauses for a second, then points to the stethoscope around Bruce’s neck. “Want to listen to the arc reactor or not?” 

Bruce’s preoccupied look transforms into a smile as he nods. He pulls the stethoscope up to his ears and reaches out to place the chestpiece in the center of Tony’s arc reactor, which can be seen glowing through his shirt even in the daylight of the lab. 

“It _does_ hum,” Bruce observes, smiling widely at Tony. As he says it, Selvig returns, wearing his own pair of green gloves, and picks up the filled vacutainers to test them. 

“Interested in the arc reactor?” Selvig asks Bruce conversationally as he holds up one of the vials of blood to the light. “Marvelous piece of tech. I’d love to know more about it, too.” 

“There’s one on my shirt,” Bruce pipes up as he takes off the stethoscope and puts it on the table. 

Selvig looks over and smiles. “Yes, it’s a nice Iron Man shirt. Mr. Stark gave it to you, I presume?” 

“No,” Tony huffs, “Pepper did.” 

“What’s Iron Man?” Bruce asks. 

“Uh,” Tony says, “A movie.” 

“There’s a movie about the arc reactor?” 

“No...” Tony trails off, trying to think of a way out of the conversation. 

Bruce frowns. “Are you lying again?” 

“Hey, why don’t you go check on the plants? You can probably water them again now,” Tony suggests quickly. 

“Okay...” Bruce agrees, but Tony can tell that he’s still suspicious as he gets up and walks over to the window, still picking at the purple bandage. 

Selvig has JARVIS test the blood samples and compare them to the previous data. As they wait for the results, Tony texts Steve to see how the search for the cure is going, not in the mood to actually call and talk to him. 

_anything yet? -TS_

The reply comes promptly. 

_We think we’ve located the perpetrator. Some kind of mad scientist. We’re planning our attack right now. We should have them in custody and working on a cure soon. -SR_

Tony sighs. 

_i wish i was out there helping instead of just babysitting -TS_

_You are helping, Tony, by taking care of Bruce. He needs you. Maybe now more than ever. -SR_

Tony looks at that last text for a long moment. _He needs you..._

Seconds later, JARVIS interrupts with the results of the test. 

“I’m not sure if it’s good or bad news, sir, but the level of gamma radiation in Master Banner’s blood is the same as it was before.” 

“So the Hulk is still here,” Tony states in wonder. He imagines what the Hulk would look like right now - scrawny and small, probably half Tony’s size. Hopefully Tony will never have to see him. If he can keep Bruce happy, the mini-Hulk will be making no unwanted appearances - not that Tony needs any more incentive to make Bruce’s short stay with them a good one. Now that he knows a cure would arrive within a day, he’s determined to make sure Bruce is _happy_ , as happy as he can make him, before he’s sent back to live his shitty life. He knows Bruce won’t remember any of it - he’s been shrunken, not sent back in time - but Tony can’t help but want to show Bruce that there is still happiness in store for him, a future where he’s wanted and cared for and _loved._ Maybe that’s what Steve meant. 

“He is indeed,” Selvig agrees, breaking Tony out of his reverie. “His mutation stayed with him even through his age-change. Whenever the rest of the Avengers find the cure, he should change right back into the Bruce you know, green guy and all.” 

Selvig seems happy about the news. Tony knows it’s a blessing and a curse and that Bruce will think the same. The Hulk is here to stay. 

Tony and Selvig analyze the results a bit more, telling JARVIS to take notes in case the teams needs more data to make the cure. Eventually they get to cleaning up the area, packing away all of Selvig’s things. Tony thanks him for coming as he heads out and Selvig says he was happy to help. Just as Tony’s about to take off his gamma-gloves, Bruce approaches him, holding his left arm out and away from his body. 

“Tony?” he says, “It’s bleeding.” 

Tony spots the dark blood seeping out from under the purple bandage and grimaces. “I’ll get you more bandages. Don’t pick at them this time.” 

Bruce nods, the look of a guilty puppy on his face. He gets back into the chair and Tony cleans up the trickle of blood with a sterile wipe before removing the old bandage and fixing him with a new one. As he applies pressure to the spot, hoping to staunch the bloodflow completely this time. 

“Did you get blood anywhere else?” Tony asks suddenly, realizing how dangerous that could be. 

“I don’t think so,” Bruce replies, sensing the worry in Tony’s voice and biting his lip. “Am I in trouble?” 

“No, don’t worry about it. I’m pretty sure there’s nothing you could do that would get you in trouble with me.” Tony grins, and Bruce smiles back, relieved. “Want to work on the robot again?” 

Bruce’s smile widens. “Definitely!” 

\---------------

Pepper returns to the tower later that evening to find her entrance to the lab barred by a curious robot that looks something like a tech'd out thermostat. It has a little red blinking light on it and it's refusing to open the door for her without a password. 

"Password," it states again when she doesn't answer the first time out of shock. Its voice sounds almost like a juvenile version of JARVIS'. 

So _this_ is what Tony and Bruce have been working on. 

"You've _got_ to be kidding me," Pepper grumbles. She tries to find a way around it but it's wired into the electronic lock on the door and there's no way to get it open manually. Eventually she gives in and humours the robot. "Um, password... Science?" 

"Password incorrect," the robot tells her, and then repeats, "Password." 

"You have terrible manners," Pepper clucks, "JARVIS would have at least said 'please'." 

"It is just a rudimentary security robot, ma'am," JARVIS supplies, apparently trying to give Tony and Bruce some credit. 

Pepper rolls her eyes. "Can you get me in?" 

"Of course, Miss Potts." 

There's a second of silence before the robot's light suddenly blinks green and the lock clicks open. She walks in the door and her jaw drops immediately at the sight of what's inside. 

Tony and Bruce have turned the entire lab into a _pillow fort_. 

Pepper's speechless as she approaches what she presumes is the entrance to the labyrinth they've created by draping the tables with sheets and standing up pillows in all shapes and sizes to make walls. There's a paper flag standing in the center of it all, bearing the words "Science Fort" messily scribbled in crayon. Before she can reach the tunnel facing her, Tony pops out of it and gasps dramatically. 

"Bruce! She found out the password!" 

Bruce crawls out after him and smiles up at Pepper, not at all as shocked as Tony. "Hi, Pepper!" 

She waves to Bruce and watches in amused disbelief as Tony gets to his feet and brushes off his jeans. 

"Actually, I didn't have to guess the password. JARVIS opened the door for me," she explains. 

"That, my dear, is called _cheating_ ," Tony complains, but leans in for a kiss anyway. As soon as they part, Bruce tugs on Tony's leg. 

"Can I tell her the password?" he asks, smiling up at Pepper, who leans down to kiss him on the head at the same time. 

"No way!" Tony scoffs. "It's a _secret_ fort, Bruce, remember?" 

Bruce looks from Pepper to Tony, clearly conflicted. "But I _like_ Pepper." 

"You can't just go around giving out the password to everyone you _like_ , Bruce, that kinda defeats the purpose..." 

Pepper rolls her eyes. "I'm starting to forget who the five-year-old is, Tony." 

Tony sticks his tongue out at her, gets down on his knees again, and crawls back into the fort. Bruce makes a move to follow, but changes his mind and turns back to Pepper to quickly whisper, "The password is 'lima beans'!" 

Pepper laughs and Bruce tugs on her hand, motioning for her to come along. Pepper can't stop herself from following her boys into the fort on all fours. She's never seen a smile like that on Bruce's face before and she's not about to turn it into a frown. 

\---------------

The three of them eat dinner together again like a family. This time they order Chinese and store the leftovers in the fridge for another day. While Bruce gets ready for bed, Pepper and Tony converse outside the door. 

“An Iron Man shirt? _Seriously?_ ” Tony says, shaking his head. 

“It was just so _cute,_ ” Pepper giggles, “If you wanted him to wear something different you should have bought him the clothes yourself.” 

“What else did you get him? A _Captain America _shirt?”__

“No, no. You’ll see what else I got him tomorrow. Speaking of Steve, did you talk to him at all today?” 

“Texted. They’ve almost found a cure.” 

As the realization hits her, her voice falters. “So tonight could already be our last night with him.” 

Tony shrugs. “Could be. Yeah, probably. But it’s not like he’ll be gone. He’ll just be... bigger. The Bruce we remember instead of the one we’ve come to know.” 

Bruce exits the bathroom a minute later, teeth brushed and ready to sleep. He goes straight to their room with them to curl between them like he had the night before, and falls asleep almost instantly in the soft glow of the arc reactor. As Pepper runs her hand through his curls, she whispers over to Tony, “You can’t tell me you won’t miss him, like this.” 

Tony thinks back to the beans, the robot, the fort, the overwhelming but _exhilarating_ feeling of being the protector of someone so vulnerable and small. 

“You’re right. I will.”

**Notes for the Chapter:**

> I hope you liked this second chapter! Sorry that it's so much shorter than the first. The third chapter is on its way - be patient! 

**Author's Note:**

> This took me like a million years to write and there's still two chapters to go! +_+ Wish me luck!
> 
> I want to thank 5harky, Hybridcomplex, and yugimutos (who also helped with the HTML!) for encouraging me and being my betas and innocence777 who inspired the entire fic with [this drawing!](http://innocence777.deviantart.com/art/The-Avengers-science-bros-happy-father-s-day-308895576)


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